Actuation system

An aircraft actuation system comprising:

• a plurality of actuators;
• a common power drive unit for driving the actuators;
• a transmission line transmitting drive from the common drive unit to the plurality of actuators;
• a plurality of movable surfaces, the movable surfaces being moved by the plurality of actuators;
• a transmission line clutch arranged in the transmission line between the power drive unit and the plurality of actuators for selectively disconnecting the power drive unit from the plurality of actuators comprising an output shaft coupled to the transmission line and a movable output shaft plate coupled to the output shaft;
• at least one sensor for sensing an abnormal load condition in the actuation system, the sensor being positioned on the transmission line;
• a clutch control, the at least one sensor being operatively coupled to the clutch control, the clutch control being configured such that when the at least one sensor senses an abnormal load condition, the clutch control is operative to disengage the transmission line clutch so as to disconnect the power drive unit from the plurality of actuators;
• an output shaft brake operative to automatically brake the actuators upon disengagement of the transmission line clutch;
• and
• wherein the transmission line clutch also comprises the output shaft brake integrated into the transmission line clutch, and automatic operation of braking is affected by means of the output shaft brake integrated into the transmission line clutch such that the output shaft brake is automatically operated upon disengagement of the transmission line clutch, and
• wherein the movable output shaft plate of the transmission line clutch moving into engagement with the output shaft brake to automatically affect braking such that the output shaft brake is automatically operated upon disengagement of the transmission line clutch.

An aircraft actuation system comprising:

• a plurality of actuators;
• a plurality of movable surfaces, the movable surfaces being moved by the plurality of actuators, wherein respective movable surfaces are arranged on respective wings of the aircraft;
• a common power drive unit for driving the actuators;
• a transmission line transmitting drive from the common drive unit to the plurality of actuators, wherein respective sections of the transmission line are connected between the power drive unit and the actuators in each wing;
• a transmission line clutch arranged in the transmission line between the power drive unit and the plurality of actuators for selectively disconnecting the power drive unit from the plurality of actuators comprising an output shaft coupled to the transmission line and a movable output shaft plate coupled to the output shaft;
• at least one sensor on each transmission line section for sensing an abnormal load condition in the actuation system;
• a clutch control, the at least one sensor being operatively coupled to the clutch control, the clutch control being configured such that when the at least one sensor senses an abnormal load condition, the clutch control is operative to disengage the transmission line clutch so as to disconnect the power drive unit from the plurality of actuators;
• an output shaft brake operative to automatically brake the actuators upon disengagement of the transmission line clutch;
• and
• wherein the transmission line clutch also comprises the output shaft brake integrated into the transmission line clutch, and automatic operation of braking is affected by means of the output shaft brake integrated into the transmission line clutch such that the output shaft brake is automatically operated upon disengagement of the transmission line clutch, and
• wherein the movable output shaft plate of the transmission line clutch moving into engagement with the output shaft brake to automatically affect braking such that the output shaft brake is automatically operated upon disengagement of the transmission line clutch
• wherein the sensors are asymmetry sensors, the output shaft brake being operative in response to detection by the asymmetry sensors of asymmetrical deployment of the movable surfaces.